I made a build profiler to understand Bun’s compile times

I built buildprof (Github), an open-source tracing tool that shows where the time goes when you compile software on Linux. Here’s a realtime video of it profiling a clean build of ripgrep: Watch the buildprof demo Sometimes, builds are slow because there is simply a lot of code to compile. But more often than not, there are fixable problems: poor parallelism, repeated work, dependency downloads or a huge compiler/linker invocation. buildprof makes all of this clearly visible, so you can see what’s worth investigating and optimizing. You run it by putting buildprof -- in front of any build command you already use: buildprof -- make -j16 buildprof -- cargo build buildprof -- ninja -C out/target buildprof -- just build buildprof -- ./dev/custom-build-script.sh buildprof records every process your build command launches, including their subprocesses (and their subprocesses…), and lays them out on one timeline. Time moves from left to right, bar width shows duration, and child processes…